Abstract
BACKGROUND: Suspected acute coronary syndrome (ACS) patients with normal intermediate high-sensitivity cardiac troponin I (hs-cTnI) concentrations, ranging from 5 ng/L to 99(th) percentile (34 ng/L for males and 16 ng/L for females), are associated with an increased prevalence and severity of coronary atherosclerosis, as well as a high risk of major adverse cardiac events (MACEs). This study aimed to evaluate the clinical utility of coronary computed tomography angiography (CCTA) in suspected ACS patients who are ruled out for myocardial infarction (MI) and have intermediate hs-cTnI concentrations in the emergency department (ED). METHODS: The retrospective longitudinal cohort study investigated two independent cohorts of 3,657 suspected ACS patients from November 2017 to January 2019. Eligible patients with intermediate hs-cTnI were divided into two groups: the CCTA group and the no-CCTA group (patients who underwent CCTA and those who did not, respectively). In both groups, patients were matched at a 1:3 ratio within a caliper of 0.05 using propensity score matching (PSM). RESULTS: A total of 540 patients were finally analyzed: 136 patients {median age 62.0 [interquartile range (IQR): 53.0-71.0] years, 75.7% men} underwent CCTA, and 404 did not [median age 62.0 (IQR: 55.0-68.0) years, 75.5% men]. The CCTA group showed a significant reduction in the rate of invasive coronary angiography (ICA) within 30 days compared to the no-CCTA group [91 (66.9%) vs. 368 (91.1%); P<0.001], without affecting MACEs (including all-cause death, MI, unplanned revascularization) within 1 year [12 (8.8%) in the CCTA group vs. 35 (8.7%) in no-CCTA group; P=0.96]. Specifically, CCTA provided clear differential diagnoses for 19% (26/136) of patients with non-obstructive coronary artery disease (CAD). CONCLUSIONS: In suspected ACS patients ruled out for MI and with intermediate hs-cTnI concentrations, CCTA offers diagnostic clarity and reduces the need for invasive procedures without affecting 1-year clinical outcomes.